Although its significance for biology has been recognized for more than a century, the molecular mechanism of allostery remains the subject of intense research. In allostery a signal from one site in a protein is transmitted to a second, often distant, site to alter its function. The ensemble model provides a framework in which dynamic and/or structural changes can contribute to allosteric regulation even within a single protein. The challenge lies in deciphering which molecular processes are critical to signal transmission. In this work we will investigate the allosteric mechanism in the Group II Biotin Protein Ligase, E.coli BirA protein. We hypothesize that BirA allostery occurs through direct coupling of dynamic changes in multiple loops to formation of residue networks. We further hypothesize that this mechanism allowed for the evolution of allostery while preserving an essential enzymatic function in post-translational biotin addition. These hypotheses will be tested using integrated genetic screening, solution biophysical measurements, x-ray crystallography, and molecular dynamics simulations. The elucidation of how allostery works in BirA will improve our general understanding of allosteric mechanisms and may prove useful for developing drugs that selectively target specific microbial BPLs and for creating Biotin Protein Ligase-based technology tools.

Public Health Relevance

Small molecule drugs that target proteins provide treatments for many diseases including bacterial infections, cancers, and neurological disorders. The research described in this proposal will enhance our understanding of the molecular mechanism of allostery, a regulatory mechanism that is used in every known biological process. Understanding of allostery in microbial Biotin Protein Ligases, the subject of these proposed studies, may enable development of drugs that specifically target biotin protein ligases from bacterial pathogens.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM129327-03
Application #
10072061
Study Section
Macromolecular Structure and Function B Study Section (MSFB)
Program Officer
Sakalian, Michael
Project Start
2019-04-01
Project End
2022-12-31
Budget Start
2021-01-01
Budget End
2021-12-31
Support Year
3
Fiscal Year
2021
Total Cost
Indirect Cost
Name
University of Maryland College Park
Department
Chemistry
Type
Earth Sciences/Resources
DUNS #
790934285
City
College Park
State
MD
Country
United States
Zip Code
20742